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Joined: Oct 2002
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Shade Tree Mechanic
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OP
Shade Tree Mechanic
Joined: Oct 2002
Posts: 103 |
I have heard that there were 2 styles of 4cyl heads that fit on the 28's.dual exhaust and single port heads.which head seems to work best for performance ? does anyone have experience with both.
isn't 28 great
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Joined: Dec 2001
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ChatMaster - 10,000
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28 chevrolet, I think someone failed to tell you that the two heads are, first the single exhaust port is not for a 28, it fits 27 back and that the only 28 head is the dual exhaust port one, as far as I know. I would not want a 27 head on a 28 and vise-a versa.
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Dec 2001
Posts: 239
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 239 |
From a standpoint of show car correctness I agree with Mr Mack 100% however, operationally I see nothing but plusses in using the 28 head on 26-28 engines. My 28 has a 27 block ( Oops ! ) and has had a 28 head installed since the forties. The valves are now small block including springs and keepers. I have two correct 28 engines and intend to install one as a final solution; however, in the interim I expect to make do and will also retain the Model A ( Plus 0.180" overbore ) pistons , rods and Vintage Weber 3/4 race camshaft. 70 MPH in overdrive is not that shabby. Herb
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Joined: Feb 2002
Posts: 168
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2002
Posts: 168 |
70 mph in a 28 Chev? Rather you than me :eek: :eek: :eek: Tim.
He who ignores the rudder answers to the rocks. When Fear advances, Logic retreats. I could go on...
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Joined: Dec 2001
Posts: 11,162
ChatMaster - 10,000
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ChatMaster - 10,000
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Tim , You should realize that Herb's 28 Chevrolet isn't exactly your Grandpa's Chevy!
The only way I feel safe with my 28 sedan crusing at 70 MPH is inside it's covered trailer behind the towing Tahoe!
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Dec 2001
Posts: 239
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 239 |
Hi Tim, I really drive it quite conservatively, I knew the guy that had it 55 years ago and he rode it hard and put it away wet about every night. The engine was even retrieved from the bottom of a cliff in Sequoia National Park once back then. I also trailer it most places but not quite at 70 mph. Herb
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Joined: Dec 2001
Posts: 217
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 217 |
I hit 70 in my 28 coupe once (according to the speedometer) but I found the car was not very aerodynamic. The visor started to flutter violently as well as the front fenders and headlights. I thought I was going to start losing parts so I backed off. Maybe the roadsters are better. Later I found out my speedometer is 5 MPH slow.
Regards, -R
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Ther's a guy down here in Aus. who runs a 28 4 door sedan, with a 28 motor that is highly modified. He claims it will do over 100 mph, which is probably true as I've been in it doing 90 mph. A bit scarey but great to feel under your feet. Should send some photos as the car is called "Peaches and cream" Chris
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Joined: Feb 2002
Posts: 168
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2002
Posts: 168 |
Roll cage, full harness, helmet and an empty airstrip. They would be my basic requirements before I would even consider taking a '28 to those sorts of speeds . Tim.
He who ignores the rudder answers to the rocks. When Fear advances, Logic retreats. I could go on...
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Joined: Feb 2003
Posts: 39
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2003
Posts: 39 |
Herb, Please Email me so we can discuss suggested engine mods for my speedster I plan on building. I rebuilt my '28 head using 350 V-8 valves, springs & keepers. Also shortened valve guides to prevent spring bind and to increase flow through ports. Increased ports to 1-5/16". Using Model A pistons and rods sounds good, did you use crank too? I would like to try and come close to copying John Gerber's bobtail. Have his autobiography which lists changes to #15 to use as a guide. Stephen Sebastian
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Joined: Jan 2002
Posts: 130
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Jan 2002
Posts: 130 |
Gee wizzz You guys haven't lived till you have been 70 mph in a Chev 4. I have a 1927 Chev 1 ton truck with an overdrive and I have been clocked at 110 klms (70 mph) on the freeways here downunder. Nothing puts a bigger smile on my face than passing a modern car in my old truck. The old girl really get wound up but don't try and stop her in hurry or some one will get hurt. Overdrive ,Olds head, higher ratio diff, Tillerson carby and oversize rear tyres all help in achieving the result. Of course the engine is balance and I have installed a steering damper that was an accessory of the time. Just ask Ken Kaufmann, Steve Kassis, Tom Meleo, Bob Hensel and Verlyn Hussman they have all driven ole Jessie on there trips to Australia. DAVE Twin 4
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Joined: Dec 2001
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ChatMaster - 10,000
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Twin four, I guess you just have a need for all that speed?
I was just wondering....Do you have Junkyard Dingos down under?
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Dec 2001
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ChatMaster - 10,000
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ChatMaster - 10,000
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I agree that a 28 head would be fine on a 27 down, but I would not want a 27 head on a 28.
Hotrodster, would you please consider doing a piece on your 4 banger speed project and sending it out or even posting the details here?
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Feb 2003
Posts: 39
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2003
Posts: 39 |
I will keep you posted, but still in the planning and parts collecting phase. I am trying to come up with a 490 frame, radiator, front end, etc. All I have are plans, a rebuilt head, aluminum manifold to fit chevy head with a winfild carb, a pontiac rear end, and a set of 27 chevy wheels. Plus I will eventually need to build a body. But I have decided on a body. I want to copy a 1920's French Amilcar wooden skiff style race body. If I decide to copy John Gerber's car, I will need to use a T frame and front end and find a good 27-28 Whippet radiator. So I still have a long way to go.
Hotrodster, would you please consider doing a piece on your 4 banger speed project and sending it out or even posting the details here?
MrMack from the Lone Star Region!
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Joined: Dec 2001
Posts: 239
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 239 |
Hi Hotroadster Sorry for the delay but I was on jury duty all last week until yesterday. For now I prefer to continue comments on this subject here in the chatroom as there seems to be some general interest. If things get too nitty gritty we can always use e-mail. There are some projects in the works that are of interest for both tour cars and speedsters. 1. I am completing a pattern for a fully counterbalanced 26-28 crankshaft which will interchange with the original. This has provisions for full pressure oiling and should provide smooth operation into the 6000 RPM range. 2. A piston and rod set will be available for more contemporary, 8:1, compression ratios. 3. With modern camshaft profiles performance with an externally near stock appearing engine is 100+ hp. 4. For speedster applications computer dynamometer simulations indicate performance in excess of 1 horsepower per cubic inch can be provided. This entails more optimized intake and exhaust configurations. 5. I consider the Model A pistons, rods and crankshaft a poor idea even though my Model A piston and rod set-up has been working for over 50 years. I use special head studs torqued to 100 Ft Lbs to preclude gasket problems. The counterbalanced Fo*rd C crank was successfully used for years in racing applications but I have not seen any information on how the clutch, flywheel, starter interface might be handled for street applications. Let me know how these items might mesh with your plans and perhaps there is some added interest out there. Herb
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Joined: Feb 2003
Posts: 39
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2003
Posts: 39 |
Herb, I have talked to a local camgrinder and he suggested either the 1957 Corvette Duntov grind or the HP 427 Fo*rd Cobra profiles. He stated that both were gentle ramp long duration profiles that would give good lift with the 1.5:1 ratio rockers.He suggested I try one or both. Too bad I don't have the exact specs or they could be put into that computer simulation you mention and tried out. 1. Did you plan on insert or babbet bearings with your new crank? 3. I have a pic of a 2-1 header that I was thinking of building for the Chevy exhaust. I recently purchased a large bore manifold that fits my Winfield S-BDD carb (!-1/4" throat). As I stated earlier, I had my intake ports opened up to 1-5/16" when the head was rebuilt. I also had the machinist install modern Chevy 1.71 intakes and 1.62 exhaust valves, dual springs, and keepers and he shortened the length of the guides during the rebuild. One of the NWVS members who runs a Chevrolet speedster says that he feels the early block is stronger because the distributer drive is in the front. What is your opinion on that, or have you even considered it? 5. I don't know anything about using Model C cranks in a Chev, but in the early 70's I knew an old guy that installed Chev cranks in Model T's when he rebuilt them. Stephen
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Joined: Dec 2001
Posts: 239
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 239 |
Hi Stephen, I expect there are many good cam profiles available but the computer model I have is sort of a plain vanilla modern small displacement 4 cyl that's probably quite optomistic for approximating the flat head and flat piston configuration of a 28 Chevy. My response to your above 1, 3 and 5 follow.
1. The crank is intended to be interchangable with stock but I intend to drill for full pressure oiling and use a larger capacity gear type pump and insert bearings. 3. Right now I am leaning toward the updraft carburetor used on 41 cabover trucks as it has a large bore and appears sort of vintage. I have a valve set-up similar to yours but the springs will depend on the cam used. I am considering the larger dia 6 cyl style cam followers. I prefer the 28 block for a variety of reasons, most obviously because my car is a 28. I have converted the center main bearing for through studs and 4130 Steel main bearing cap but don't expect it to be necessary. 5. I see no conflict here. The Chevy crank was probably an improvement over Model T and the C Crank was preferred for both Model A and Chevy race engines.
Herb
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Joined: Jan 2002
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Herb I have a minor interest here, having owned a few 'hotted up cars over the years. I've still got it in my system, but not for my 28 coach.
There are quite a few 'modified' Chev 4 engines here in Aust. lightened flywheels from just a few pounds lighter, to totally flat like a modern one, 3 port Olds heads (of which I have 2), FA and FB Chev heads are the same, Durant rods, which are longer, therefore instant higher compression, multi (up to 12 plastic) bladed fans to suck more air in, and Tilitson carbies. These are updraft, have over 1 1/4" bore and all adjustable jets. Cam grinds which one guy here specailises in etc. All seem to work well.
But "Peaches and cream" (the 28 sedan I mentioned in an earlier post) has full drilled and pressured crank (28 Chev crank), modern harmonic balancer, slipper bearings, extractors, twin SU carbs etc and does do over 100 mph on 34 Master wire wheels, modern shocks and sway bars.
The 'best for the littlest effort' is Ozjim's 28 tourer which sits comfortably over 60 mph all day with very few mods. Maybe we could convince him to tell the story of his mods
Chris
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Joined: Dec 2001
Posts: 239
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 239 |
Hi Chris, We seem to be gathering a small gold mine of information here that needs to be permanently put on line for everyone to read or contribitute to. You mention a couple of items above that I don't recall being discussed yet but certainly should be. 1. I ran a chopped flywheel for years on my 235 High Torque six, but the 4 cyl clutch and flywheel is a weight choppers dream. I also would like to hear if someone has used a 41-48 type clutch disk and modern ball bearing throwout. 2. The fours ride like a brick which is nice for dirt roads or cross county fields but can definitely benefit from softer springs, good shocks and ,if you plan to go fast, juice brakes. I had 50 Chevy brakes on my 32 and it definitely gives you peace of mind. I'm not sure what sway bars do for a four leaf spring suspension but the discussion would be most interesting. Herb
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Joined: Dec 2001
Posts: 10,379 Likes: 1
Technical Advisor ChatMaster - 10,000
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Technical Advisor ChatMaster - 10,000
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Hi Herb, We have that capability now. If someone would summarize the information it will be posted in TECH TALK and retained.
RAY Chevradioman http://www.vccacolumbiariverregion.org/1925 Superior K Roadster 1928 Convertible, Sport, Cabriolet 1933 Eagle, Coupe 1941 Master Deluxe 5-Passenger Coupe 1950 Styleline Deluxe 4-Door Sedan 1950 Styleline Deluxe Convertible 2002 Pontiac, Montana, Passenger Van 2014 Impala, 4-Door Sedan, White Diamond, LTZ 2017 Silverado, Double Cab, Z71, 4X4, White, Standard Bed, LTZ If you need a shoulder to cry on, pull off to the side of the road. Death is the number 1 killer in the world.
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Joined: Dec 2001
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ChatMaster - 10,000
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Herb have you tried one of Verlyn Husman's modified throw-out bearings. I have a "new Spare engine and Tranny I am building up for a spare and intend to use one in it. I also really would like to have a good Olds head or a very good 28 head. I think a four with dualheaders sounds cool also. One of the guys in out club has a 25 speedster with headers, and umbrella! (Oldchevman) I had to edit the first line, I had mis spelled Verlyn's names....Imagine that, Me mispellin anyethang!
Life's a long winding trail, love Jesus and ride a good horse!
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MrMack
I thought I'd by throwing in my 2 cents worth would get this sort of thing you suggested underway. We all know a little bit, but combined we're nearing expert status. Re cluthes, some of the blokes out here run Holden (Aust. family sedan) cluthes, and others have done various throwout bearing modifications again using Holden product. Re the Olds head, as I said I have 2 of these, and the 3 exhaust ports are certianly a bonus, however you would not run the existing manifolds, and the valves are way to small, with a Tilitson updraught, a set of extractors and bigger valves, it would definately be worth the effort. Another draw back is that you have to modify your firewall as the back exhaust port extend beyond the back of the head Re the brakes, the bakes aren't the problem as I can lock all four wheels on my 28 coach (by using super soft linings, and slightly modified adjustment) but the tyres are too narrow and they just skid
I wholeheartedly support your idea and would only to happy happy to help where I can
Chris
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Joined: Jan 2002
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ChatMaster - 750
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Gents I just noticed on ebay a 27 motor with what looks like a Tilitson carby on it, it hasn't had a bid even with a start price of $9.99, the cary would be worth more than that Chris
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Joined: Dec 2001
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I do agree on the stoppers being able to slide the tires, I think sliding those little narrow tires isn't too hard to do. I have the idea of useing wire spoke wheels of the 18 inch diameter with the drop center rims and use a 28 down to a 24 cowl to do a proper "hotrod" open wheel speedster. I rather doubt that Louis Chevy ever worried about stopping, just GOOOIING! An open air landing strip, With lots of bales of straw, and a roll cage and football suit also are in mind.
Have any of you known of a 4 cylinder Chevy powered sprint car of the 1930's? I once crewed for a four cylinder dragster powered by a 1932 model "B" F.o.r.d engine ,I am thinking it was an overhead cam valve in head engine, It was originally a sprint car that we modified into a dragster.. It was an X class national champ in either 1956 or 1957, it was the last year the NHRA Nationals were held in Oklahoma City.
Life's a long winding trail, love Jesus and ride a good horse!
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Joined: Mar 2004
Posts: 26
Grease Monkey
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Grease Monkey
Joined: Mar 2004
Posts: 26 |
It all depends on what you are going to do with your reworked chevy. I can tell you from experience that a deers eyes - and yours - get mighty BIG when they are standing in the road and you have just come off of a long down grade with hot brakes. My 27 speadster (bits & pieces) has only the stock rear brakes. You grab foot brake and emergincy at times. I wonder where I can get an ancker. MrMack you need to pick up a copy of Gerber's Book. He ran an outlaw sprint car running chevy 4's. I have trimmed a flywheel for the later plate and the newer style throwout bearing. Between the flywheel and preasure place, I think that the lose in weight was somewhere around 40 pounds. I saw going to use the stock cluch fork with modified guide bolts. I have not gotten any farther than that, so cannot advise. Gaby
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