project engine bonneville

[jlop3s91]

can i pressure test the engine with it out on the engine stand like i have or is this a really dumb question hahahah 😳

 

[dan2286]

can i pressure test the engine with it out on the engine stand like i have or is this a really dumb question hahahah 😳

You can do a compression test on an engine stand, but it will not determine the compression ration the engine has. To do the compression test, you will just need to hook a battery up to the starter and perform the test the same way you would with it in the car.

To find the compression ratio, technically you would have to take apart the engine and do some measuring and formulas. You should be able to do some research and see what numbers and parts to look for to see what engines had what compression.

 

[jlop3s91]

alright ill search the web and also im just having a thought which could be a bad thig but seeing as all pontiac v8s are the same size externally (correct me if im wrong) and the external parts are interchangable .....i could technically put a 400 in my bonneville and swap the heads intake... starter? water pump? ..im not really familar with all this so im trying to learn hahha please correct me if this stuf is completely wrong and cant be done

 

[82 G.P.]

I'm completing a 350 pontiac into an 82 Grand Prix lj, luckly i found a 78 gp with a 301 in it. I used the engine mount brackets off of the engine and the mount pads for a 78 with a 301. I used the factory manifolds with a little porting, I also use the same y-pipe, but note the 301 and 265 pontiac is an inch thinner than its bigger brothers so we had to add pipe to the center of it. The sway was extremley easy. The mount holes are in the frame and you can find a 265 or a 301 in any 78-81 pontiac g-bodys or even regals, and no clearance issues. I can answer any questions about this swap, except why i went with single exhaust

 

[jlop3s91]

i did some research on the heads on my motor and i think they are actually #17 heads 72cc if im not mistaken ....im having a hard time figuring out how to ID my heads though im just guessing because they have 17 on the middle exhaust ports and the date code is j187 which was confusing me ..............wont these heads give me terrible compression i looked at chart on this website http://www.wallaceracing.com/cratio0001.htm

 

[shotgun]

Are you sure the engine is not a 350?

 

[jlop3s91]

ill check the engine code and date again but i think the date was 67 and they didnt make 350s in 67
http://www.yearone.com/yodnn/tech/Vehic ... fault.aspx

 

[Bonnewagon]

Could be someone used 68' 350 heads on a 67' 326.

 

[jlop3s91]

if the engine is a 326 wont those heads be bad for it?

 

[Bonnewagon]

The 350 is just a bigger bore 326. The #17 heads are 2 barrel small valve according the your YearOne link. There should be no valve/deck clearance issues. But even those are high compression heads by 70's - 80's standards. A 71' or later set of 350 heads would give around 7.5 or less compression.