Engine Position-Tech Help Needed

[Patrick]

I have purchased both the S&P LS1 Engine Plates and the Holley LS1 Swap Plates to compare.

Here is what I found: Compared to the S&P Plates, the Holley Plates move the engine back(closer to the firewall) by almost 1.25". However, the Holley Plates RAISE the engine by about 7/16".


So the question is..When building a car for handling what is better:

Engine forward but lower?
or
Engine back but higher?

[paul67]

back, the further the engine is to the centre the better also lower if poss

[Patrick]

back, the further the engine is to the centre the better also lower if poss

I agree..however with the plates I have, I dont have the option of back and lower. So given the numbers above, which is the better of the two?

[Matt@RFR]

1 1/4" engine setback won't make a damn bit of difference. I would opt for stock longitudinal location and down some.

[andrewb70]

1 1/4" engine setback won't make a damn bit of difference. I would opt for stock longitudinal location and down some.

I would think that 1 1/4 inches would make a difference considering your moving the transmission back the same distance.

Andrew

[Ron S]

You may want to check header clearance before you make a desicion.That was the problem I found.Some mounts aren't real generous with steering box and frame clearance

[Patrick]

You may want to check header clearance before you make a desicion.That was the problem I found.Some mounts aren't real generous with steering box and frame clearance

I am using the Holley/Hooker Long Tube LS1 headers which clear with either set of plates, however they are really tight with the S&P mounts (I had to demple one tube to clear the pitman arm). Clearance with the Holley Plates is not an issue.

I am just trying to determine which set offers better overall weight distribution.

[paul67]

The plates that move the engine back.

[jannes_z-28]

In the installation guide for LS1 engines that GM sells (#88959384) they have a drawing showing how the engine mounts should be located to get the backplane at the same location as an CSB engine.

From seeing pictures of the Hooker plates I believe that they have done them according to the GM spec.

The S&P plates are done the "easy" way and using one existing bolthole in the block and therefore moves the engine/trans forward.

Jan

[ProStreet R/T]

In the terms of overall effect keep it LOWER.



When you look at the change in weight distribution by moving the engine back 1 1/2" it doesn't do a damn thing. By comparison moving the battery to the trunk has a far more profound change in weight balance. To see any major benefit you need to move the engine 6-8" rearward.

[nitrovette]

The plates i got for the vette put my motor 1 1/4 inch forward,so i had to move my 700 forward and remake the crossmember.The thing was i modified my hooker sidepipes to fit ls1 flanges ,when finished the sidepipes came out right in the right location,if i had set the motor back the 1 1/4 inch they wouldve been jambed up against my rear tires,so it helped me by using them.

[Patrick]

FWIW,

I welded up the Holley plates. Then drilled and tapped them to sit lower but in their original position (closer to the firewall).

I ended up with plates that position the motor tight to the firewall (Holley's position) and Lower (S&P's position).

The headers now have plenty of clearance.