Inliners International Forums General Discussion Engines inliner potential

Hello, I'm new to the forum and recently sent in my application to the Inliners. I'm a returning semi old school hot rodder and looking to start a new project. I have a back ground in inliners including AMC, Chevy and Oldsmobile and want to use a inline six in my project. I'm looking for a motor with potential to make 260-270 HP and power a 2000-2200 lb street car. Parts need to be attainable along with good power in a reasonbly light and small package. I'm a bit partial to the GMC 270's but insure about availble buildable cores. As i said i'm old school and remember the drag racers running sixes in the 70's like Sizemore, Siebert & Bugenski, "Holeshot Six" and all the others who swam against the current.
Any ideas or suggestions would be appreciated.
thanks, Motoretro

Welcome..The inline knowledge base here is wide and deep. I ended up with a 250 Chevy at about 240/260 HP.I had a 300 Ford also. The reason I went with the Chevy was because I had a cam,lifters,and some .040 pistons (307 v/8) on hand. It was a $$$$$ deal !!!Those old GMCs are hard to pass up also. I understand that they are using some 454 Chevy parts in them now. Some of the Inliner guy run them at Bonneville and would be a good resource to you. The Power Manual in the Club Stuff section is a must and will save you a bunch of time and money in the long run. Jump in and get your feet wet...SCRAP

I like the "erly iron", but here 'newer is better'.

If your building a custom light weight car, a built 250 (to the 270+/- CID) is probably much lighter ("More bang per pound".) than any other. One horsepower per CID+ "no problem".......

Check with Larry/Novaman/twisted six for exact info on this.

Good luck.

Welcome.What vehicle will be the recipient of this engine?Any pics?Good luck!

Hello,
There is a tremendous amount of info out there on various different inline engines although to be honest, I'm leaning to the GMC 270H-302 engines..I'm just hoping good rebuildable cores are available...?? As for what its going into, the Poli-Form 27 lakes roadster really has my attention. I'm going to be in California in late Oct.I hope to get a up close and personal look at one. Here's a link: http://www.poli-form.com/Catalog/body/27lakes.html
Pretty salty huh? I want to sort out the engine/trans thing before i purchase a body so if any one knows of available Jimmys out there please let me know.
thanks, Motoretro

Check with Patrick's on that, they know where.

Watch the "Classifieds" on the Inliners website. Currently the Larrowes in Oregon are offering 302 blocks and heads--stripped, magnafluxed, and pricey. Others will come up from time to time. Tom Langdon has had them in the past. Blocks, heads, complete engines, and other parts are often advertised in the *12-Port News*.

A 302 built right can exceed 260 horsepower, but the torque potential is greater. Low- to mid-range torque is the great strength of these engines.

God's Peace to you.

d
Inliner #1450

Thanks for all the info,
Motoretro

There are tons of them around, you just need to know how and where to look for them.

GMC 302s were used from '52 on in 450 series trucks. They will have a serial number on the doorpost ID plate that will read something like 453-30-12345 as an example. The two middle numbers, 30, indicate 302. If the middles numbers are 24, its a 248, 27 - it's a 270 and so forth.

Civilian 302s are harder to find than the sealed military blocks which to me seem pretty plentiful. Converting a military block is a pain in the rumpus because they were sealed and many of the accessories and the HydraMatic transmission (these are the only way military 302s are offered) along many other parts are useless and require parts searching when you use them in a hot rod or civilian application. I just finished converting a military 302 and it is running in my '51 6 volt positive ground 3/4 ton Huckster. Goes like the wind and it's pretty much a stock motor with some hidden upfits and tweaks. Nothing crazy.

GMC 270s are VERY plentiful and were used in everything from military trucks during WW2 and in civilian trucks up to the early 60s. You'll find them in medium duty trucks from 47-59 and in light duty (pickups) from 55-59. They are a great motor sporting the same stroke and slightly smaller bore as I'm sure you know.

We have a "WANTED" section on our oldGMCtrucks.com forums pages where you can post an ad for whatever you want. We are GMC freaks and have over 2800 eyes looking all the time so we know where a lot of bodies are buried.

What section of the country are you in?

Geeze, thanks for all the info. I'm in mid Michigan but get around quite a bit(retired). My son is a fireman in Lexington, KY(yes he was at the airliner crash on Sunday)and we may be moving to area around Asheville, NC so travel is not a problem. Thanks for the link too... a 270H or 302 is what i'm looking for. Parts or whole, Perf. stuff needed too.
thanks, Motoretro

There is a GMC sitting in a wreckers in Butte Montanna .... complete less intake and exhaust manifolds, actually its still in the orginal chassis.

GMC 302 street engines are expensive to build,no performance parts a readily available,as compared to other engines.Realistic street hp is around 250 before you get into even more expensive modified heads etc.Racing 302's have mega power,but they have little to nothing in common with street engines.But the 302 is a fantastic piece,the best vintage engine by far,but not exactly light or compact.
Light and compact?,a supercharged 250 Chevy might be a good choice,uses readily some available small block V-8 parts,should produce 275+ HP easily without becoming too nastly for regular driving.The AMC,Mopar or Ford inlines are also will fit the description.

Listen to Tony.

It's horsepower (per pound) that's important, especialy for a lightweight fiberglass car.

The 270/302s were the best in the 50/60s for 3,000# coupes/sedeans where the higher torque was a factor on the 1/4 mile Drag Strip.

The 250/292 will rev to 7,000+ as they have 7 mains. The 292 is 50# heaver & might be to tall for a roadster however.

Good luck

If the Balance job has been done right the 250/292s will rev Over that 7000 rpm mark. I have buzzed my 250 to 8000 many times.and Have heard of others buzzing to 10,000 Not that i would want to psh the 10,000 rpm mark But 8000 isn't a problem. My 250 wouldn't think twice at hitting the 8000. But when i built it I made sure that at 8000 the valves wouldn't be floating.